Patient characteristics of spontaneous breathing and mechanically ventilated RSV-infected infants.

Nr: number of patients; kg: kilograms; T = 0 for ventilated patients is < 1 hour before intubation, for non-ventilated patients on admission; T = 24 is 24 hours after the first sample in both groups; NS: not significant; PaCO2: arterial carbon dioxide tension; BE: base excess; Bic: bicarbonate; FiO2: fraction of inspired oxygen; Vt: Tidal volume.